Total tau protein in cerebrospinal fluid and diffusion-weighted MRI as an early diagnostic marker for Creutzfeldt-Jakob disease

Clinical and Genetic Characteristics of the Heidenhain Variant of Creutzfeldt-Jakob Disease

BACKGROUND

The Heidenhain variant of Creutzfeldt-Jakob disease (HvCJD), as a rare phenotype of CJD, has been under-recognized. We aim to elucidate the clinical and genetic features of HvCJD and investigate the differences of clinical features between genetic and sporadic HvCJD to improve our understanding of this rare subtype.

METHOD

HvCJD patients admitted to the Xuanwu Hospital from February 2012 to September 2022 were identified, and published reports on genetic HvCJD cases were also reviewed. The clinical and genetic features of HvCJD were summarized, and the clinical features between genetic and sporadic HvCJD were compared.

RESULTS

A total of 18 (7.9%) HvCJD patients were identified from 229 CJD cases. Blurred vision was the most common visual disturbance at the disease's onset, and the median duration of isolated visual symptoms was 30.0 (14.8-40.0) days. DWI hyperintensities could appear in the early stage, which might help with early diagnosis. Combined with previous studies, nine genetic HvCJD cases were identified. The most common mutation was V210I (4/9), and all patients (9/9) had methionine homozygosity (MM) at codon 129. Only 25% of cases had a family history of the disease. Compared to sporadic HvCJD, genetic HvCJD cases were more likely to present with non-blurred vision visual symptoms at onset and develop cortical blindness during the progression of the disease.

CONCLUSIONS

HvCJD not only could be sporadic, but also, it could be caused by different PRNP mutations. Sporadic HvCJD was more likely to present with blurred vision visual symptoms at onset, and genetic HvCJD was more likely to develop cortical blindness with the disease's progression.

Sporadic Creutzfeldt-Jakob Disease: Diagnosing Typical and Atypical Presentations under Limited Circumstances

INTRODUCTION

Sporadic Creutzfeldt-Jakob disease (sCJD) is a transmissible disorder of the central nervous system caused by the transformation of normal prion protein into an abnormal misfolded form. The process begins spontaneously and runs a vicious cycle to cause spongiform encephalopathy, rapidly resulting in death. Amply described in the western literature, CJD is scarcely reported in Asia due to certain limitations including missed diagnosis, under-reporting, and rarity of the disease. Brain MRI, electroencephalogram, cerebrospinal fluid testing, and biopsy of the infected brain tissue support the diagnosis in cases of clinical suspicion. However, the diagnosis can still be made with limited available resources in developing countries.

METHOD

A review of CJD cases evaluated in the neurology department of a tertiary care hospital in Pakistan was done from 2002 to 2018.

RESULTS

Eleven cases labeled as sCJD are identified based on the European MRI-CJD consortium criteria. This is the first study on CJD from Pakistan, which includes both the typical and atypical presentations.

CONCLUSION

Even with limited testing available, the diagnosis of CJD can be made with confidence in the developing countries, provided the suspicion is kept high in cases of rapid onset dementia and acute behavioral changes.

Case Report: Extremely Early Detection of Preclinical Magnetic Resonance Imaging Abnormality in Creutzfeldt-Jakob Disease With the V180I Mutation

The diagnosis of presymptomatic Creutzfeldt–Jakob disease (CJD) is challenging. The levels of total tau protein, 14-3-3 protein, and protease-resistant isoform of prion protein (PrP^res) in the cerebrospinal fluid; periodic sharp wave complexes on electroencephalography; and diffusion-weighted imaging (DWI) of brain magnetic resonance imaging (MRI) have all been used to diagnose symptomatic CJD, but none of these markers have been established in the diagnosis of presymptomatic CJD. Here, we report a case of genetic CJD with the V180I mutation in which a small punctate cortical hyperintensity was detected on DWI 6 months before symptom onset and 9 months before diagnosis. Presymptomatic CJD is currently impossible to diagnose because of the lack of established early diagnostic markers. However, since MRI is increasingly used in daily clinical practice, the chance detection of such DWI abnormalities would have important implications in terms of providing a clue to examine a highly specific early diagnostic marker to be developed in the future for CJD. This will allow presymptomatic intervention by disease-modifying therapy in the near future.

Diagnostic value of diffusion-weighted brain magnetic resonance imaging in patients with sporadic Creutzfeldt-Jakob disease: a systematic review and meta-analysis

OBJECTIVE

To evaluate the diagnostic yield and performance of DWI in patients with sporadic CJD (sCJD).

METHODS

A systematic literature search of the MEDLINE and EMBASE databases was performed, since their inception up to July 28, 2020. Pooled diagnostic yield of diffusion-weighted imaging was calculated using DerSimonian-Laird random-effects model. Pooled diagnostic performance of DWI (sensitivity, specificity, and area under the curve) in diagnosing sCJD among patients with rapidly progressive dementia was calculated using a bivariate random-effects model. Subgroup analysis and meta-regression were performed.

RESULTS

Fifteen original articles with a total of 1144 patients with sCJD were included. The pooled diagnostic yield was 91% (95% confidence interval [CI], 86 to 94%); summary sensitivity, 91% (95% CI, 84 to 95%); and specificity, 97% (95% CI, 94 to 99%). The area under the hierarchical summary receiver operating characteristic curve was 0.99 (95% CI, 0.97-0.99). Simultaneous involvement of the neocortex and striatum was the most common finding, and the neocortex was the most common site to be involved on DWI followed by striatum, thalamus, and cerebellum. Subgroup analysis and meta-regression demonstrated significant heterogeneity among the studies associated with the reference standards used for diagnosis of sCJD.

CONCLUSIONS

DWI showed excellent diagnostic value in diagnosis of sporadic Creutzfeldt-Jakob disease among patients with rapidly progressive dementia. Simultaneous involvement of the neocortex and striatum was the most common finding, and the neocortex was the most common site to be involved on diffusion-weighted imaging followed by striatum, thalamus, and cerebellum.

KEY POINTS

• The pooled diagnostic yield of diffusion-weighted imaging in sporadic Creutzfeldt-Jakob disease was 91%. • The diagnostic performance of diffusion-weighted imaging for predicting sporadic Creutzfeldt-Jakob disease among patients with rapidly progressive dementia was excellent, with pooled sensitivity, 91%, and specificity, 97%. • Simultaneous involvement in the neocortex and striatum was most commonly seen on diffusion-weighted imaging (60%), followed by the neocortex without striatum (30%), thalamus (21%), cerebellum (8%), and striatum without neocortex (7%).

Clinical Use of Improved Diagnostic Testing for Detection of Prion Disease

Prion diseases are difficult to recognize as many symptoms are shared among other neurologic pathologies and the full spectra of symptoms usually do not appear until late in the disease course. Additionally, many commonly used laboratory markers are non-specific to prion disease. The recent introduction of second-generation real time quaking induced conversion (RT-QuIC) has revolutionized pre-mortem diagnosis of prion disease due to its extremely high sensitivity and specificity. However, RT-QuIC does not provide prognostic data and has decreased diagnostic accuracy in some rarer, atypical prion diseases. The objective of this review is to provide an overview of the current clinical utility of fluid-based biomarkers, neurodiagnostic testing, and brain imaging in the diagnosis of prion disease and to suggest guidelines for their clinical use, with a focus on rarer prion diseases with atypical features. Recent advancements in laboratory-based testing and imaging criteria have shown improved diagnostic accuracy and prognostic potential in prion disease, but because these diagnostic tests are not sensitive in some prion disease subtypes and diagnostic test sensitivities are unknown in the event that CWD transmits to humans, it is important to continue investigations into the clinical utility of various testing modalities.

MM2-type sporadic Creutzfeldt-Jakob disease: new diagnostic criteria for MM2-cortical type

OBJECTIVE

To clinically diagnose MM2-cortical (MM2C) and MM2-thalamic (MM2T)-type sporadic Creutzfeldt-Jakob disease (sCJD) at early stage with high sensitivity and specificity.

METHODS

We reviewed the results of Creutzfeldt-Jakob disease Surveillance Study in Japan between April 1999 and September 2019, which included 254 patients with pathologically confirmed prion diseases, including 9 with MM2C-type sCJD (MM2C-sCJD) and 10 with MM2T-type sCJD (MM2T-sCJD), and 607 with non-prion diseases.

RESULTS

According to the conventional criteria of sCJD, 4 of 9 patients with MM2C- and 7 of 10 patients with MM2T-sCJD could not be diagnosed with probable sCJD until their death. Compared with other types of sCJD, patients with MM2C-sCJD showed slower progression of the disease and cortical distribution of hyperintensity lesions on diffusion-weighted images of brain MRI. Patients with MM2T-sCJD also showed relatively slow progression and negative results for most of currently established investigations for diagnosis of sCJD. To clinically diagnose MM2C-sCJD, we propose the new criteria; diagnostic sensitivity and specificity to distinguish 'probable' MM2C-sCJD from other subtypes of sCJD, genetic or acquired prion diseases and non-prion disease controls were 77.8% and 98.5%, respectively. As for MM2T-sCJD, clinical and laboratory features are not characterised enough to develop its diagnostic criteria.

CONCLUSIONS

MM2C-sCJD can be diagnosed at earlier stage using the new criteria with high sensitivity and specificity, although it is still difficult to diagnose MM2T-sCJD clinically.

Clinical Laboratory Tests Used To Aid in Diagnosis of Human Prion Disease

Prion diseases are a group of rapidly progressive and always fatal neurodegenerative disorders caused by misfolded prion protein in the brain. Although autopsy remains the gold-standard diagnostic tool, antemortem laboratory testing can be performed to aid in the diagnosis of prion disease. This review is meant to help laboratory directors and physicians in their interpretation of test results. Laboratory assays to detect both nonspecific biomarkers of prion disease and prion-specific biomarkers can be used. The levels of nonspecific biomarkers in cerebrospinal fluid (CSF) are elevated when rapid neurodegeneration is occurring in the patient, and these markers include 14-3-3, tau, neuron-specific enolase, S100B, and alpha-synuclein. These markers have various sensitivities and specificities but are overall limited, as the levels of any of these analytes can be elevated in nonprion disease that is causing rapid damage of brain tissue. Prion-specific assays used in clinical laboratory testing are currently limited to two options. The first option is second-generation real-time quaking-induced conversion (RT-QuIC) performed on CSF, and the second option is Western blotting of a brain biopsy specimen used to detect protease-resistant prion protein. Although both tests have exquisite specificity, RT-QuIC has a sensitivity of 92 to 97.2% in symptomatic individuals, compared to the brain biopsy Western blot sensitivity of 20 to 60%. RT-QuIC was added to the Centers for Disease Control and Prevention's diagnostic criteria for prion disease in 2018. Other caveats of laboratory testing need to be considered, as sporadic, genetic, and acquired forms of prion disease have different clinical and laboratory presentations, and these caveats are discussed. Laboratory testing plays an important role in the diagnosis of prion disease, which is often challenging to diagnose.

Cortical Hyperintensity on Diffusion-weighted Images as the Presymptomatic Marker of Sporadic Creutzfeldt-Jakob Disease

We herein report a sporadic Creutzfeldt-Jakob disease (sCJD) patient followed from the presymptomatic phase to death. A 67-year-old woman had abnormal hyperintense cortical lesions on diffusion-weighted magnetic resonance imaging (MRI) one year before the onset. The levels of 14-3-3 protein and total tau protein, and findings from a real-time quaking-induced conversion test were normal at first but became abnormal after disease onset. Although there are four reports of presymptomatic sCJD identified by MRI, this is the first case report in which all three biomarkers had been assessed before and after the disease onset. MRI might be the most sensitive modality for detecting presymptomatic sCJD patients.

Drug-induced Creutzfeldt-Jakob disease-like syndrome: early CSF analysis as useful tool for differential diagnosis

We report the case of a 78-year-old man who showed a subacute onset of severe cognitive impairment, ataxia, tremor, stimulus sensitive myoclonus and hypophonia. Since a few weeks, he received a treatment with a combination of tricyclic antidepressants for mood disorder. The clinical picture mimicked Creutzfeldt-Jakob disease (CJD), but we could rule out this diagnosis by means of cerebrospinal fluid (CSF) analysis, which showed normal level of tau protein and Aβ_1-42, being also negative for CSF 14-3-3 protein. A complete clinical recovery was observed after the discontinuation of antidepressants. So far, some cases of drug-induced CJD-like syndrome have been described. In our experience, early CSF analysis shows high diagnostic usefulness in order to exclude CJD.

Sporadic Creutzfeldt-Jakob disease

Sporadic Creutzfeldt-Jakob disease (CJD), the most common human prion disease, is generally regarded as a spontaneous neurodegenerative illness, arising either from a spontaneous PRNP somatic mutation or a stochastic PrP structural change. Alternatively, the possibility of an infection from animals or other source remains to be completely ruled out. Sporadic CJD is clinically characterized by rapidly progressive dementia with ataxia, myoclonus, or other neurologic signs and, neuropathologically, by the presence of aggregates of abnormal prion protein, spongiform change, neuronal loss, and gliosis. Despite these common features the disease shows a wide phenotypic variability which was recognized since its early descriptions. In the late 1990s the identification of key molecular determinants of phenotypic expression and the availability of a large series of neuropathologically verified cases led to the characterization of definite clinicopathologic and molecular disease subtypes and to an internationally recognized disease classification. By showing that these disease subtypes correspond to specific agent strain-host genotype combinations, recent transmission studies have confirmed the biologic basis of this classification. The introduction of brain magnetic resonance imaging techniques such as fluid-attenuated inversion recovery and diffusion-weighted imaging sequences and cerebrospinal fluid biomarker assays for the detection of brain-derived proteins as well as real-time quaking-induced conversion assay, allowing the specific detection of prions in accessible biologic fluids and tissues, has significantly contributed to the improved accuracy of the clinical diagnosis of sporadic CJD in recent years.

Diagnostic and prognostic power of CSF Tau in amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease that still lacks reliable diagnostic biomarkers. This study aims to evaluate the diagnostic and prognostic potential of CSF total Tau (t-Tau), phospho-Tau (p-Tau) and p-Tau/t-Tau ratio in ALS patients using CSF neurofilament light (NFL) as the reference biomarker.

METHODS

Eighty-five incident ALS, 30 ALS-mimicking (AM) diseases and 51 other non-neurodegenerative diseases (ONND) were included in the study.

RESULTS

ALS patients had higher levels of CSF t-Tau and lower p-Tau/t-Tau ratio than AM (p = 0.005 and p = 0.006) and ONND (p < 0.001). CSF t-Tau levels discriminated ALS from AM with a sensitivity of 69% and specificity of 60%, and from ONND with a sensitivity of 88% and specificity of 51%. These values were lower than the accuracy of CSF NFL in ALS (sensitivity 86% and specificity 87% in distinguishing ALS from AM and sensitivity 83% and specificity 75% from ONND); CSF t-Tau correlated with progression rate and SNIP. CSF p-Tau did not show relation with any ALS clinical features. CSF NFL significantly correlated with all considered clinical parameters. High levels of CSF t-Tau and NFL were related to poor survival.

CONCLUSION

CSF t-Tau showed no reliable diagnostic significance but the relation between the high levels of CSF t-Tau and short survival suggests the potential prognostic role of this biomarker in ALS. However, CSF NFL was confirmed to be the most reliable and efficient tool for diagnosis and prediction of clinical progression and survival in ALS patients.

Cerebrospinal Fluid Biomarker-Based Diagnosis of Sporadic Creutzfeldt-Jakob Disease: A Validation Study for Previously Established Cutoffs

BACKGROUND

Several biomarkers have been proposed to discriminate sporadic Creutzfeldt-Jakob disease (sCJD) from other dementias and control cases. However, their clinical accuracy depends on the PRNP codon 129 genotype, leaving it unclear how well established markers behave in untested conditions.

METHODS

We analyzed 14-3-3, tau, p-tau levels, and the p-tau/tau ratio in a population sample collected from Polish hospitals including nondementia, dementia, and definite sCJD cases and validated their parameters according to previously established cutoffs. Additionally, the correlation between biomarkers and disease duration as well as the influence of the PRNP129 polymorphism are reported.

RESULTS

The tau levels and p-tau/tau ratios differed considerably between sCJD and clinically characterized non-CJD cases (p < 0.001). p-tau was only elevated in sCJD when compared to cases without dementia (p < 0.05). Tau and the p-tau/tau ratio showed a sensitivity of 95 and 100%, respectively, in detecting sCJD cases. A negative correlation between tau levels and disease duration, but not the timing of lumbar puncture was observed.

CONCLUSION

The present findings confirmed the value of the p-tau/tau ratio as a robust sCJD biomarker and suggest a role for tau as prognostic marker.

Validation and utilization of amended diagnostic criteria in Creutzfeldt-Jakob disease surveillance

Objective

To validate an amended protocol for clinical diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD) including real-time quaking-induced conversion (RT-QuIC) and to observe its use in CJD surveillance.

Methods

In the framework of a prospective epidemiologic study, all neuropathologically confirmed cases with sCJD who received CSF RT-QuIC analysis during diagnostic workup (n = 65) and a control group of individuals without CJD (n = 118) were selected to investigate the accuracy of an amended diagnostic protocol. The patients had been referred to the German National Reference Center for Transmissible Spongiform Encephalopathies. The influence of the amended protocol on incidence figures was evaluated in the context of 3 years of surveillance activity (screened cases using 14-3-3 test n = 18,789, highly suspicious cases of CJD n = 704). Annual incidences were calculated with current criteria and the amended protocol.

Results

The amended protocol showed a sensitivity of 97% and a specificity of 99%. When it was applied to all suspected cases who were referred to the reference center, the assessed incidence of CJD increased from 1.7 to 2.2 per million in 2016.

Conclusion

CJD surveillance remains challenging because information from external health care institutions can be limited. RT-QuIC shows excellent diagnostic accuracy when applied in the clinical setting to symptomatic patients. Data for RT-QuIC alone when applied as a general screening test are not available yet. We propose an amended research protocol that improves early and accurate clinical diagnosis of sCJD during surveillance activities. The use of this protocol will probably lead to a significant increase of the incidence rate.

Classification of evidence

This study provides Class III evidence that for patients with suspected sCJD, criteria for clinical diagnosis plus the CSF RT-QuIC accurately identifies patients with sCJD (sensitivity 97%, specificity 99%).

Alternative application of Tau protein in Creutzfeldt-Jakob disease diagnosis: Improvement for weakly positive 14-3-3 protein in the laboratory

The 14-3-3 protein has been used as a biomarker for the diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). However, weakly positive 14-3-3 leads to false positive results and an incorrect diagnosis. We attempted to use quantitative data for tau protein to provide an accurate diagnosis based on weak 14-3-3 protein. Sixty-two patients with sCJD, including pathologically confirmed, clinically definite, and probable cases, and 89 non-CJD patients were investigated based on a Korean population. Among them, 20 sCJD and 14 non-CJD showed weakly positive 14-3-3. The total tau (t-tau) and phosphorylated tau (p-tau) protein levels were measured by ELISA, and the p-tau to t-tau ratio (p/t ratio) was calculated. The combined use of the 14-3-3 protein assay, t-tau levels, and p/t ratio improved the specificity of diagnosis compared with the use of the 14-3-3 protein assay alone (47% for 14-3-3 alone; 85.94% for 14-3-3 combined with t-tau; 90.62% for 14-3-3 combined with the p/t ratio). In addition, 18 of 20 sCJD and 12 of 14 non-CJD who were weakly positive for 14-3-3 were positive for the p/t ratio and negative for the p/t ratio, respectively. When used in combination with the 14-3-3 protein, the tau protein is useful as a biomarker for the precise diagnosis of sCJD.

Mathematical models for the diffusion magnetic resonance signal abnormality in patients with prion diseases

In clinical practice signal hyperintensity in the cortex and/or in the striatum on magnetic resonance (MR) diffusion-weighted images (DWIs) is a marker of sporadic Creutzfeldt–Jakob Disease (sCJD). MR diagnostic accuracy is greater than 90%, but the biophysical mechanisms underpinning the signal abnormality are unknown. The aim of this prospective study is to combine an advanced DWI protocol with new mathematical models of the microstructural changes occurring in prion disease patients to investigate the cause of MR signal alterations. This underpins the later development of more sensitive and specific image-based biomarkers. DWI data with a wide a range of echo times and diffusion weightings were acquired in 15 patients with suspected diagnosis of prion disease and in 4 healthy age-matched subjects. Clinical diagnosis of sCJD was made in nine patients, genetic CJD in one, rapidly progressive encephalopathy in three, and Gerstmann–Sträussler–Scheinker syndrome in two. Data were analysed with two bi-compartment models that represent different hypotheses about the histopathological alterations responsible for the DWI signal hyperintensity. A ROI-based analysis was performed in 13 grey matter areas located in affected and apparently unaffected regions from patients and healthy subjects. We provide for the first time non-invasive estimate of the restricted compartment radius, designed to reflect vacuole size, which is a key discriminator of sCJD subtypes. The estimated vacuole size in DWI hyperintense cortex was in the range between 3 and 10 µm that is compatible with neuropathology measurements. In DWI hyperintense grey matter of sCJD patients the two bi-compartment models outperform the classic mono-exponential ADC model. Both new models show that T₂ relaxation times significantly increase, fast and slow diffusivities reduce, and the fraction of the compartment with slow/restricted diffusion increases compared to unaffected grey matter of patients and healthy subjects. Analysis of the raw DWI signal allows us to suggest the following acquisition parameters for optimized detection of CJD lesions: b = 3000 s/mm² and TE = 103 ms. In conclusion, these results provide the first in vivo estimate of mean vacuole size, new insight on the mechanisms of DWI signal changes in prionopathies and open the way to designing an optimized acquisition protocol to improve early clinical diagnosis and subtyping of sCJD.

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An advanced DWI acquisition scheme was applied to 15 patients with suspected sCJD.

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Data fitting with two bi-compartment models outperformed the classic ADC model.

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In affected GM T₂ values were increased, diffusion was more hindered or restricted.

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For the first time an estimate of the restricted compartment radius was provided.

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The radius may reflect vacuole size, which is a key discriminator of sCJD subtypes.

White matter involvement in sporadic Creutzfeldt-Jakob disease

Sporadic Creutzfeldt-Jakob disease is considered primarily a disease of grey matter, although the extent of white matter involvement has not been well described. We used diffusion tensor imaging to study the white matter in sporadic Creutzfeldt-Jakob disease compared to healthy control subjects and to correlated magnetic resonance imaging findings with histopathology. Twenty-six patients with sporadic Creutzfeldt-Jakob disease and nine age- and gender-matched healthy control subjects underwent volumetric T₁-weighted and diffusion tensor imaging. Six patients had post-mortem brain analysis available for assessment of neuropathological findings associated with prion disease. Parcellation of the subcortical white matter was performed on 3D T₁-weighted volumes using Freesurfer. Diffusion tensor imaging maps were calculated and transformed to the 3D-T₁ space; the average value for each diffusion metric was calculated in the total white matter and in regional volumes of interest. Tract-based spatial statistics analysis was also performed to investigate the deeper white matter tracts. There was a significant reduction of mean (P = 0.002), axial (P = 0.0003) and radial (P = 0.0134) diffusivities in the total white matter in sporadic Creutzfeldt-Jakob disease. Mean diffusivity was significantly lower in most white matter volumes of interest (P < 0.05, corrected for multiple comparisons), with a generally symmetric pattern of involvement in sporadic Creutzfeldt-Jakob disease. Mean diffusivity reduction reflected concomitant decrease of both axial and radial diffusivity, without appreciable changes in white matter anisotropy. Tract-based spatial statistics analysis showed significant reductions of mean diffusivity within the white matter of patients with sporadic Creutzfeldt-Jakob disease, mainly in the left hemisphere, with a strong trend (P = 0.06) towards reduced mean diffusivity in most of the white matter bilaterally. In contrast, by visual assessment there was no white matter abnormality either on T₂-weighted or diffusion-weighted images. Widespread reduction in white matter mean diffusivity, however, was apparent visibly on the quantitative attenuation coefficient maps compared to healthy control subjects. Neuropathological analysis showed diffuse astrocytic gliosis and activated microglia in the white matter, rare prion deposition and subtle subcortical microvacuolization, and patchy foci of demyelination with no evident white matter axonal degeneration. Decreased mean diffusivity on attenuation coefficient maps might be associated with astrocytic gliosis. We show for the first time significant global reduced mean diffusivity within the white matter in sporadic Creutzfeldt-Jakob disease, suggesting possible primary involvement of the white matter, rather than changes secondary to neuronal degeneration/loss.

Sporadic Creutzfeldt-Jakob disease (sCJD) is considered primarily a disease of grey matter. However, Caverzasi et al. now show a global decrease in mean diffusivity in white matter. The changes appear to be associated with reactive astrocytic gliosis and activated microglia, and suggest primary involvement of the white matter in sCJD.

Increased α-synuclein levels in the cerebrospinal fluid of patients with Creutzfeldt-Jakob disease

Recent studies have shown that cerebrospinal fluid (CSF) levels of α-synuclein (α-syn) are highly elevated in patients with Creutzfeldt-Jakob disease (CJD) compared to controls. However, the diagnostic value of CSF α-syn in CJD has not been established. To confirm whether CSF α-syn is increased in CJD and is a useful marker for this disease, two independent enzyme-linked immunoabsorbent assays (ELISAs) specific for α-syn were used: ELISA 211-FL140, which is specific for full-length α-syn, and ELISA N19-FL140, which is specific for the full-length and associated C-terminal truncated forms of α-syn. CSF samples from 24 patients with CJD and 24 controls were assessed in this study. We found that samples from the CJD patients showed significantly higher levels of CSF α-syn compared to controls in both ELISA (211-FL140 or N19-FL140) tests (P = 0.0467 and P = 0.0010, respectively). However, there was a considerable overlap in the concentration ranges of the two groups of subjects. We also measured the levels of total tau (t-tau) protein in these samples and found that CSF t-tau levels were 5-10-times higher in the CJD group (P < 0.0001) compared with the controls. When the CSF t-tau and α-syn levels were combined, the area under the ROC curve (AUC) was slightly increased in clinically diagnosed CJD cases (AUC of 0.964) relative to an AUC of 0.943 for increased CSF t-tau alone. The combined use of CSF α-syn and t-tau levels may be a useful biomarker for the diagnosis of CJD.

Ethics in prion disease

This paper is intended to discuss some of the scientific and ethical issues that are created by increased research efforts towards earlier diagnosis, as well as to treatment of, human prion diseases (and related dementias), including the resulting consequences for individuals, their families, and society. Most patients with prion disease currently are diagnosed when they are about 2/3 of the way through their disease course (Geschwind et al., 2010a; Paterson et al., 2012b), when the disease has progressed so far that even treatments that stop the disease process would probably have little benefit. Although there are currently no treatments available for prion diseases, we and others have realized that we must diagnose patients earlier and with greater accuracy so that future treatments have hope of success. As approximately 15% of prion diseases have a autosomal dominant genetic etiology, this further adds to the complexity of ethical issues, particularly regarding when to conduct genetic testing, release of genetic results, and when or if to implement experimental therapies. Human prion diseases are both infectious and transmissible; great care is required to balance the needs of the family and individual with both public health needs and strained hospital budgets. It is essential to proactively examine and address the ethical issues involved, as well as to define and in turn provide best standards of care.

Diagnosing sporadic creutzfeldt-jakob disease in a patient with a suspected status epilepticus in the intensive care unit

Objective. Several tests are available in the diagnostics of sporadic Creutzfeldt-Jakob disease (sCJD); however, none of these is conclusive. We review the values of these tests, from an intensive care unit (ICU) perspective. Methods. Case report and review of the literature. Results. A 53-year-old woman initially presenting with psychiatric symptoms developed myoclonus and was admitted 1 month later to the ICU with a suspected nonconvulsive status epilepticus and respiratory insufficiency, probably due to extensive antiepileptic drug therapy. Typical MRI and EEG findings and a positive 14-3-3 protein led to the diagnosis of sCJD. All treatments were terminated, and autopsy confirmed sCJD. Conclusions. Clinical signs combined with MRI, EEG, and 14-3-3 and/or tau protein determination might be sufficient to diagnose or exclude sCJD and may therefore prevent the application of unnecessary diagnostic tests.

[Unilateral Creutzfeld-Jakob disease: report of a probable case on electroclinical, MRI and biological criteria]

We report the case of a 70-year-old man who developed probable unilateral Creutzfeldt-Jakob disease. Clinically, he presented with right hemiparesis, progressive aphasia, temporospatial disorientation and cerebellar ataxia and later on, myoclonia. The MRI showed a hypersignal from the left caudate in DWI with decreased ADC. Repeated electroencephalograms showed a slow background rhythm in the left hemisphere with superimposed periodic, biphasic and triphasic sharp-wave complexes in the left temporal region. Death occurred after 5weeks. Although exceptional, unilateral Creutzfeldt-Jakob disease was retained as possible.

Cerebrospinal fluid biomarker supported diagnosis of Creutzfeldt-Jakob disease and rapid dementias: a longitudinal multicentre study over 10 years

To date, cerebrospinal fluid analysis, particularly protein 14-3-3 testing, presents an important approach in the identification of Creutzfeldt–Jakob disease cases. However, one special point of criticism of 14-3-3 testing is the specificity in the differential diagnosis of rapid dementia. The constant observation of increased cerebrospinal fluid referrals in the national surveillance centres over the last years raises the concern of declining specificity due to higher number of cerebrospinal fluid tests performed in various neurological conditions. Within the framework of a European Community supported longitudinal multicentre study (‘cerebrospinal fluid markers’) we analysed the spectrum of rapid progressive dementia diagnoses, their potential influence on 14-3-3 specificity as well as results of other dementia markers (tau, phosphorylated tau and amyloid-β_1–42) and evaluated the specificity of 14-3-3 in Creutzfeldt–Jakob disease diagnosis for the years 1998–2008. A total of 29 022 cerebrospinal fluid samples were analysed for 14-3-3 protein and other cerebrospinal fluid dementia markers in patients with rapid dementia and suspected Creutzfeldt–Jakob disease in the participating centres. In 10 731 patients a definite diagnosis could be obtained. Protein 14-3-3 specificity was analysed for Creutzfeldt–Jakob disease with respect to increasing cerebrospinal fluid tests per year and spectrum of differential diagnosis. Ring trials were performed to ensure the comparability between centres during the reported time period. Protein 14-3-3 test specificity remained high and stable in the diagnosis of Creutzfeldt–Jakob disease during the observed time period across centres (total specificity 92%; when compared with patients with definite diagnoses only: specificity 90%). However, test specificity varied with respect to differential diagnosis. A high 14-3-3 specificity was obtained in differentiation to other neurodegenerative diseases (95–97%) and non-neurological conditions (91–97%). We observed lower specificity in the differential diagnoses of acute neurological diseases (82–87%). A marked and constant increase in cerebrospinal fluid test referrals per year in all centres did not influence 14-3-3 test specificity and no change in spectrum of differential diagnosis was observed. Cerebrospinal fluid protein 14-3-3 detection remains an important test in the diagnosis of Creutzfeldt–Jakob disease. Due to a loss in specificity in acute neurological events, the interpretation of positive 14-3-3 results needs to be performed in the clinical context. The spectrum of differential diagnosis of rapid progressive dementia varied from neurodegenerative dementias to dementia due to acute neurological conditions such as inflammatory diseases and non-neurological origin.

Desmoplakin as a potential candidate for cerebrospinal fluid marker to rule out 14-3-3 false positive rates in sporadic Creutzfeldt-Jakob disease differential diagnosis

BACKGROUND

The detection of a 14-3-3 elevated level in cerebrospinal fluid (CSF) is a part of the diagnostic criteria for probable sporadic Creutzfeldt-Jakob disease (sCJD), as defined by the WHO. However, some pathological conditions associated with acute neuronal damage may result in a positive 14-3-3 test and thereby reduce test specificity in sCJD.

OBJECTIVE

Desmoplakin has been previously identified as up-regulated CSF protein in sCJD and these studies aimed to investigate its diagnostic utility and compare it with two known CSF markers, 14-3-3 and tau.

METHODS AND RESULTS

We tested CSF levels of 14-3-3, tau and desmoplakin in 58 sCJD patients and 81 control patients including 45 cases with an elevated 14-3-3 level due to other disease than sCJD. We detected an elevated CSF level of desmoplakin in 78% of the sCJD patients, while 14-3-3 (88%) and tau (91%) showed a higher positive rate. However, the false positive rate of newly tested desmoplakin was significantly lower in comparison to 14-3-3 and tau, and it accounted for only 11% versus 56% and 35%, respectively. Further reduction of false positive rates was achieved by combination of elevated tau level with a positive desmoplakin test. Moreover, in the non-sCJD group, desmoplakin level did not correlate with the level of both above-mentioned CSF markers, whereas a clear correlation was observed in the sCJD group.

CONCLUSION

Desmoplakin showed a low positive rate accompanied by a very low false positive rate. Thus, we conclude that desmoplakin is a promising candidate for supportive CSF marker to rule out 14-3-3 false positive cases in sCJD differential diagnosis.

High sensitivity of an ELISA kit for detection of the gamma-isoform of 14-3-3 proteins: usefulness in laboratory diagnosis of human prion disease

BACKGROUND

The gamma-isoform of the 14-3-3 protein (14-3-3 gamma) is expressed in neurons, and could be a specific marker for neuronal damage. This protein has been reported as a detectable biomarker, especially in the cerebrospinal fluid (CSF) of Creutzfeldt-Jakob disease (CJD) patients by Western blotting (WB) or enzyme-linked immunosorbent assays (ELISAs). Western blotting for 14-3-3 gamma is not sensitive, and the reported data are conflicting among publications. An ELISA specific for 14-3-3 gamma is not available.

METHODS

CJD patients (n=114 sporadic CJD patients, 7 genetic CJD, and 3 iatrogenic CJD) and 99 patients with other neurodegenerative diseases were examined in this study. The CSF samples obtained were analyzed by Western blotting for 14-3-3 gamma, and by ELISA for total tau protein. We evaluated the sensitivity and specificity of the newly developed sandwich ELISA for 14-3-3 gamma.

RESULTS

The cut-off value of the 14-3-3 gamma ELISA was >1, 683 AU/ml; and sensitivity was 95.2%, with 72.7% specificity. This specificity was the same for the total tau protein ELISA. Seven CJD cases were negative by WB but positive using the 14-3-3 gamma ELISA, indicating that the ELISA is more sensitive. All 21 cases of early stage CJD could be diagnosed using a combination of the 14-3-3γ ELISA and diffusion weighted MR imaging (DWI-MRI).

CONCLUSION

The 14-3-3 gamma ELISA was more sensitive than conventional WB, and was useful for laboratory diagnosis of CJD, similar to the ELISA for the tau protein. Using DWI-MRI and these ELISA tests on CSF, diagnosis of CJD will be possible even at early stages of the disease.

Rapidly progressive corticobasal degeneration syndrome

Introduction

Corticobasal syndrome (CBS) has a heterogeneous clinical presentation with no specific pathologic substratum. Its accurate diagnosis is a challenge for neurologists; in order to establish CBS definitively, postmortem confirmation is required. Some clinical and radiological features can help to distinguish it from other neurodegenerative conditions, such as Creutzfeldt-Jakob disease (CJD).

Clinical Case

A 74-year-old woman presented with language impairment, difficulty in walking and poor attentiveness that had begun 10 days before. Other symptoms, such as asymmetrical extra-pyramidal dysfunction, limb dystonia and ‘alien limb’ phenomena, were established over the next 2 months, with rapid progression. Death occurred 3 months after symptom onset. Laboratory results were normal. Initially, imaging only showed restricted diffusion with bilateral parieto-occipital gyri involvement on DWI-MRI, with unspecific EEG changes. An autopsy was performed. Brain neuropathology confirmed sporadic CJD (sCJD).

Conclusions

CBS is a heterogeneous clinical syndrome whose differential diagnosis is extensive. CJD can occasionally present with clinical characteristics resembling CBS. MRI detection of abnormalities in some sequences (FLAIR, DWI), as previously reported, has high diagnostic utility for sCJD diagnosis – especially in early stages – when other tests can still appear normal. Abnormalities on DWI sequencing may not correlate with neuropathological findings, suggesting a functional basis to explain the changes found.

A polymorphism in the YWHAH gene encoding 14-3-3 eta that is not associated with sporadic Creutzfeldt-Jakob disease (CJD)

14-3-3 proteins are abundantly expressed in the brain, particularly neuronal tissue and are thought to serve multiple biological functions involved in neuronal development and cell growth and death. Recent studies have shown associations of 14-3-3 genes with neurodegenerative disorders based on their chromosomal linkage to these diseases and to regulatory functions for the nervous system. Although the role of 14-3-3 proteins in the pathogenesis of prion diseases remains unknown, the detection of altered levels of isoforms of the 14-3-3 protein in the cerebrospinal fluid is considered a biomarker for diagnosis of sporadic Creutzfeldt-Jakob disease (sCJD). To identify other susceptibility genes for prion disease, we examined nucleotide variations in YWHAH, a gene encoding 14-3-3 eta. This case-control study included 182 sCJD patients and 206 healthy Koreans. Polymerase chain reaction was used to amplify open reading frame and some 3'-untranslated region (UTR) in exon 2, and direct sequencing was carried out. One polymorphism, 753 G/A, was detected in the 3'-UTR of exon 2 on the YWHAH. The genotype distribution and allele frequencies of the YWHAH 753 G/A polymorphism were not significantly different between controls and sCJD patients. This finding indicates that YWHAH 753 G/A polymorphism is unlikely to be linked to genetic susceptibility or have a modifying effect in sCJD. On analysis stratified by the prion protein gene 129 or 219 genotype, no significant relation was found in genotype and allele frequencies of the YWHAH 753G/A. This is the first genetic association study of YWHAH with sCJD populations.

Decreased CSF transferrin in sCJD: a potential pre-mortem diagnostic test for prion disorders

Sporadic Creutzfeldt-Jakob-disease (sCJD) is a fatal neurodegenerative condition that escapes detection until autopsy. Recently, brain iron dyshomeostasis accompanied by increased transferrin (Tf) was reported in sCJD cases. The consequence of this abnormality on cerebrospinal-fluid (CSF) levels of Tf is uncertain. We evaluated the accuracy of CSF Tf, a ‘new’ biomarker, as a pre-mortem diagnostic test for sCJD when used alone or in combination with the ‘current’ biomarker total-tau (T-tau). Levels of total-Tf (T-Tf), isoforms of Tf (Tf-1 and Tf-β2), and iron saturation of Tf were quantified in CSF collected 0.3–36 months before death (duration) from 99 autopsy confirmed sCJD (CJD+) and 75 confirmed cases of dementia of non-CJD origin (CJD-). Diagnostic accuracy was estimated by non-parametric tests, logistic regression, and receiver operating characteristic (ROC) analysis. Area under the ROC curve (AUC), sensitivity, specificity, positive and negative predictive values (PV), and likelihood ratios (LR) of each biomarker and biomarker combination were calculated. We report that relative to CJD-, CJD+ cases had lower median CSF T-Tf (125,7093 vs. 217,7893) and higher T-tau (11530 vs. 1266) values. AUC was 0.90 (95% confidence interval (CI), 0.85–0.94) for T-Tf, and 0.93 (95% CI, 0.89–0.97) for T-Tf combined with T-tau. With cut-offs defined to achieve a sensitivity of ∼85%, T-Tf identified CJD+ cases with a specificity of 71.6% (95% CI, 59.1–81.7), positive LR of 3.0 (95% CI, 2.1–4.5), negative LR of 0.2 (95% CI, 0.1–0.3), and accuracy of 80.1%. The effect of patient age and duration was insignificant. T-Tf combined with T-tau identified CJD+ with improved specificity of 87.5% (95%CI, 76.3–94.1), positive LR of 6.8 (95% CI, 3.5–13.1), negative LR of 0.2 (95% CI, 0.1–0.3), positive-PV of 91.0%, negative-PV of 80.0%, and accuracy of 86.2%. Thus, CSF T-Tf, a new biomarker, when combined with the current biomarker T-tau, is a reliable pre-mortem diagnostic test for sCJD.

Tau and p-tau as CSF biomarkers in dementia: a meta-analysis

BACKGROUND

To evaluate the value of total tau (tau) and phosphorylated tau (p-tau) in cerebrospinal fluid (CSF) in the differential diagnosis of dementia, more specifically: dementia with Lewy Bodies (DLB), frontotemporal lobar degeneration (FTLD), vascular dementia (VaD), and Creutzfeldt-Jacob disease (CJD).

METHODS

A systematic literature search was performed to identify studies on tau and p-tau in DLB, FTLD, VaD and CJD. Tau concentrations were compared to healthy controls and to subjects with Alzheimer's disease (AD) using random effect meta-analysis. Outcome measures were Cohen's delta, sensitivity and specificity.

RESULTS

Compared to controls, tau concentrations are moderately elevated in DLB, FTLD and VaD, while p-tau concentrations are only slightly elevated in DLB and not elevated in FTLD and VaD. Compared to AD, lower tau concentrations differentiated DLB with a sensitivity of 73% and a specificity of 90%, FTLD with sensitivity and specificity of 74%, and VaD with a sensitivity of 73% and a specificity of 86%. Relative to AD, lower p-tau values differentiated FTLD with a sensitivity of 79% and specificity of 83%, and VaD with a sensitivity of 88% and a specificity of 78%. CJD is characterized by extremely elevated tau concentrations with a sensitivity of 91% and a specificity of 98% vs. AD.

CONCLUSIONS

CSF tau concentrations in DLB, FTLD and VaD are intermediate between controls and AD patients. Overlap with both controls and AD patients results in insufficient diagnostic accuracy, and the development of more specific biomarkers for these disorders is needed. CJD is characterized by extremely increased tau values, resulting in a sensitivity and specificity that exceeds 90%.

The prion diseases

The prion diseases are a family of rare neurodegenerative disorders that result from the accumulation of a misfolded isoform of the prion protein (PrP), a normal constituent of the neuronal membrane. Five subtypes constitute the known human prion diseases; kuru, Creutzfeldt-Jakob disease (CJD), Gerstmann-Sträussler-Scheinker syndrome (GSS), fatal insomnia (FI), and variant CJD (vCJD). These subtypes are distinguished, in part, by their clinical phenotype, but primarily by their associated brain histopathology. Evidence suggests these phenotypes are defined by differences in the pathogenic conformation of misfolded PrP. Although the vast majority of cases are sporadic, 10% to 15% result from an autosomal dominant mutation of the PrP gene (PRNP). General phenotype-genotype correlations can be made for the major subtypes of CJD, GSS, and FI. This paper will review some of the general background related to prion biology and detail the clinical and pathologic features of the major prion diseases, with a particular focus on the genetic aspects that result in prion disease or modification of its risk or phenotype.

Establishment of a standard 14-3-3 protein assay of cerebrospinal fluid as a diagnostic tool for Creutzfeldt-Jakob disease

Periodic sharp wave complexes observed on an electroencephalographic recording and the presence of a 14-3-3 protein in the cerebrospinal fluid (CSF) are both included in the diagnostic criteria for the Creutzfeldt-Jakob disease (CJD) supplied by the World Health Organization; however, the presence or absence of the 14-3-3 protein in the CSF is sometimes difficult to discern on a western blot because of equivocal bands. The goal of this study was to establish a standard 14-3-3 protein assay and to determine the threshold level of a 14-3-3 protein that can be assayed by western blot. We searched for the most suitable isoform of the 14-3-3 protein to test for in protein assays, and the most sensitive antibody among four antibodies with an affinity for 14-3-3. We measured the levels of all 14-3-3 isoforms in 112 patients with CJD and in 100 patients with other diseases. We compared the performances of four different antibodies. We carried out a semi-quantitative analysis of γ-isoform levels using the LAS 3000 system, which was capable of producing a digital image from the luminescence on a western blot. We determined that the most suitable isoform of the 14-3-3 protein for conducting a standardized assay was the γ-isoform. Among the four commercially available antibodies for this protein, the most sensitive and specific was 18647 (IBL, Japan). We report the high repeatability of the detection of the 14-3-3 protein by this antibody to the γ-isoform, showing that western blot can be used for semi-quantitative analysis.

Elevated levels of tau protein in cerebrospinal fluid of patients with probable Creutzfeldt-Jakob disease

INTRODUCTION

A definitive diagnosis of Creutzfeldt-Jakob disease (CJD) can only be made by neuropathologic examination and demonstration of typical pathologic changes and the pathologic prion protein in central nervous tissues. This study investigated the diagnostic sensitivity and specificity of the microtubule-association protein tau in cerebrospinal fluid (CSF) from Chinese patients with sporadic CJD.

METHODS

Two hundred two CSF samples from clinically suspected patients with sporadic CJD were analyzed for tau protein by enzyme-linked immunosorbent assay and for the signal transduction regulatory protein 14-3-3 protein by immunoblot.

RESULTS

Remarkably increased levels of tau protein and increased incidence of 14-3-3 positivity were observed in probable CJD, when compared with possible CJD and others. With a threshold of 1400 pg/mL, tau determination showed a sensitivity of 90% and a specificity of 94% for the diagnosis of probable CJD. The combination of raised tau and positive 14-3-3 increased the specificity but slightly reduced the sensitivity. Statistical analysis indicated that the raised level of tau positively correlated with the presence of 14-3-3 in CSF but not with other main clinical features, eg, age, gender, clinical manifestations and sampling time.

CONCLUSIONS

These data suggest that Chinese patients with probable CJD have similar increased levels of tau in the CSF as in Caucasian patients. Measurement of CSF tau will be another potential technique for antemortem CJD diagnosis.

[Sporadic Creutzfeldt-Jakob disease: two cases in intensive care]

Prion diseases or spongiform encephalopathies are a family of rare neurodegenerative diseases characterized by long incubation periods associated with slow, irreversible and invariably fatal evolution. In humans, they are classified as sporadic, acquired and hereditary or genetic. Diagnosing sporadic "Creutzfeldt-Jakob Disease" (sCJD) is a real challenge for the intensive care physician, given the variability in its clinical presentation and its low incidence. The cases of two patients admitted to the Intensive Care Unit are presented. After ruling out other diseases, they were diagnosed with sCJD with a likelihood level according to the World Health Organization Classification. Clinical and laboratory diagnostic aspects of the disease were analyzed, highlighting the utility of 14-3-3 protein identification in the cerebrospinal fluid.

Cerebrospinal fluid biomarkers in human prion diseases

Cerebrospinal fluid (CSF) is the main component of the brain extracellular space and participates in the exchange of many biochemical products in the CNS. Consequently, CSF contains a dynamic and complex mixture of proteins that reflect the physiological or pathological state of the CNS. Changes in the CSF proteome have been described in various neurodegenerative disorders. These alterations are also thought to reflect pathological changes in the brain, and thus understanding them will contribute to a better awareness of the pathophysiology that underlies these disorders. Proteomics offers a new methodology for the analysis of pathological changes and mechanisms occurring in neurodegenerative processes and provides the possibility of novel biomarker discovery in order to supplement faster, earlier and more precise diagnosis. In general, the following criteria have to be applied in order to qualify a protein or a gene as a potential biomarker: the selected parameters have to be sensitive (able to detect the abnormalities at early stage of disease), specific (to allow differential diagnosis), reproducible with a high positive predictive value, and should allow for disease monitoring as well as a potential therapeutic response. In Creutzfeldt–Jakob disease, two major approaches have been followed that aim to detect the pathological form of the prion protein (PrPSc) in various peripheral tissues, while other approaches look for surrogate parameters that are a consequence of the neurodegenerative process. While the amount of abnormal disease-related PrPSc in CSF and blood in human transmissible spongiform encephalopathies appears to be extremely low, the development of a PrPSc-based biomarker was hampered by technical problems and detection limits. However, a variety of other proteins have been investigated in the CSF, and recently a variety of potential biomarkers have been reported that contribute to clinical diagnosis. Already established markers are 14-3-3, β-amyloid, tau-protein and phosphorylated isoforms, S100b, as well as neuron-specific enolase. Since some of these markers display certain limitations, the search continues. This review summarizes current knowledge of biomarker development in prion diseases and discusses perspectives for new approaches.

Updated clinical diagnostic criteria for sporadic Creutzfeldt-Jakob disease

Several molecular subtypes of sporadic Creutzfeldt–Jakob disease have been identified and electroencephalogram and cerebrospinal fluid biomarkers have been reported to support clinical diagnosis but with variable utility according to subtype. In recent years, a series of publications have demonstrated a potentially important role for magnetic resonance imaging in the pre-mortem diagnosis of sporadic Creutzfeldt–Jakob disease. Magnetic resonance imaging signal alterations correlate with distinct sporadic Creutzfeldt–Jakob disease molecular subtypes and thus might contribute to the earlier identification of the whole spectrum of sporadic Creutzfeldt–Jakob disease cases. This multi-centre international study aimed to provide a rationale for the amendment of the clinical diagnostic criteria for sporadic Creutzfeldt–Jakob disease. Patients with sporadic Creutzfeldt–Jakob disease and fluid attenuated inversion recovery or diffusion-weight imaging were recruited from 12 countries. Patients referred as ‘suspected sporadic Creutzfeldt–Jakob disease’ but with an alternative diagnosis after thorough follow up, were analysed as controls. All magnetic resonance imaging scans were assessed for signal changes according to a standard protocol encompassing seven cortical regions, basal ganglia, thalamus and cerebellum. Magnetic resonance imaging scans were evaluated in 436 sporadic Creutzfeldt–Jakob disease patients and 141 controls. The pattern of high signal intensity with the best sensitivity and specificity in the differential diagnosis of sporadic Creutzfeldt–Jakob disease was identified. The optimum diagnostic accuracy in the differential diagnosis of rapid progressive dementia was obtained when either at least two cortical regions (temporal, parietal or occipital) or both caudate nucleus and putamen displayed a high signal in fluid attenuated inversion recovery or diffusion-weight imaging magnetic resonance imaging. Based on our analyses, magnetic resonance imaging was positive in 83% of cases. In all definite cases, the amended criteria would cover the vast majority of suspected cases, being positive in 98%. Cerebral cortical signal increase and high signal in caudate nucleus and putamen on fluid attenuated inversion recovery or diffusion-weight imaging magnetic resonance imaging are useful in the diagnosis of sporadic Creutzfeldt–Jakob disease. We propose an amendment to the clinical diagnostic criteria for sporadic Creutzfeldt–Jakob disease to include findings from magnetic resonance imaging scans.

[A case of Creutzfeldt-Jakob disease with stroke-like episode as an initial symptom]

A 79-year-old woman was admitted to our hospital, due to acute onset of left hemiparesis and disturbance of consciousness. Although her symptoms improved temporarily, she developed gait disturbance and cognitive deterioration 2 months after the onset. After that, she presented with myoclonus and startle response, followed by akinetic mutism within 8 months after the onset. Serial EEGs revealed no periodic synchronous discharge. Serial diffusion-weighted MRIs showed that high intensity lesions, which initially limited to the right cerebral cortex, gradually spread to the bilateral cerebral cortices and basal ganglia, with relative sparing of central gyri, medial occipital cortices, and hippocampus. Prion protein gene analysis revealed a point mutation (Val-->Ile) at codon 180. The result of this patient suggests that this type of CJD might be associated with an atypical clinical course such as stroke-like episode and selective involvement of cortical and subcortical lesions.

Cerebrospinal fluid tau protein is not a biological marker in amyotrophic lateral sclerosis

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder leading to progressive motor neuron cell death. Etiopathogenesis is still imperfectly known and much effort have been undertaken to find a biological marker that could help in the early diagnosis and in the monitoring of disease progression. Cerebrospinal fluid (CSF) concentrations of tau, an axonal microtubule-associated protein, have been measured in ALS with levels found increased in some studies and unchanged in others.

METHODS

Total CSF tau level was assayed in a population of ALS patients (n = 57) and controls (n = 110) using a specific ELISA method.

RESULTS

No significant differences in the median CSF tau levels between ALS cases and controls were found [ALS: 126 pg/ml (78-222); controls: 112 pg/ml (71-188), P = ns]. In the ALS group, the bulbar-onset patients showed increased CSF tau levels as compared with the spinal-onset cases. These differences might be related to the higher age of the bulbar-onset patients. Further, no correlations were found between CSF tau concentrations and the rate of progression of the disease.

CONCLUSIONS

These results do not support the hypothesis that total CSF tau protein is a reliable biological marker for ALS.

MR imaging of familial Creutzfeldt-Jakob disease: a blinded and controlled study

BACKGROUND AND PURPOSE

The E200K mutation of the PRNP (prion protein) gene is the most common cause of familial Creutzfeldt-Jakob disease (fCJD), which has imaging and clinical features that are similar to the sporadic form. The purpose of this study was to conduct a controlled and blinded evaluation of the sensitivity and specificity of MR imaging in this unique population.

MATERIALS AND METHODS

We compared the MR imaging characteristics of 15 early stage familial CJD patients (age, 60 +/- 7 years) with a group of 22 healthy subjects from the same families (age, 61 +/- 8 years). MR imaging included diffusion-weighted imaging (DWI), T2-weighted fast spin-echo imaging, and a fluid-attenuated inversion recovery (FLAIR) sequence. The scans were rated for abnormalities by an experienced neuroradiologist blind to diagnosis, group assignment, age, and sex.

RESULTS

Thirteen of 15 fCJD subjects had abnormal MR imaging. FLAIR signal intensity abnormality in the caudate or putamen nuclei demonstrated a sensitivity of 87% and specificity of 91%. DWI abnormality in the caudate nucleus showed a sensitivity of 73% and a specificity of 100%. Abnormalities in the thalamus (6 patients), cingulate gyrus (6 patients), frontal lobes (4 patients), and occipital lobes (3 patients) were best detected with DWI. No signal intensity abnormalities were demonstrated in the cerebellum. T2-weighted and T1-weighted sequences were uninformative.

CONCLUSIONS

FLAIR and DWI abnormalities in the caudate nucleus and putamen offer the best sensitivity and specificity for diagnosing fCJD. Our findings support recent recommendations that MR imaging should be added to the diagnostic evaluation of CJD.